I know this thread is looking for the oldest person posting here, but how about the oldest still active in slot racing? I nominate my friend Earl Sharer, who is 88 and is still building cars from scratch and is still building/modifying routed tracks. Here's a picture from 9 years ago of Earl hanging out with Mike Steube prior to a vintage F1 race (just before D3 got started).

Yeah, Earl was 79 and racing against Steube.